Gaseous discharge display panel with scanning anode base plate assembly including resistive masses

ABSTRACT

A display panel including an array of gas-filled cells being arranged in upper display and lower scan sections of aligned cells with upper and lower cell pairs separated by a common cathode electrode. The lower scan section is further defined by scanning anode strips applied into slots formed in a lower insulator base plate with discrete resistive masses filling a portion of the slots while bridging a discontinuity in the applied scanning anode provided in a ledge area of the base plate. A common bus formed across the end of the base plate ledge forms a single electrical terminal interconnecting the scanning anodes for connection to an external power supply. In the method of making the display panel a conductive material solution is applied to the floor of the lower insulator base plate slots in an operation that is interrupted for providing the discontinuity therein which is filled by a discrete mass of resistive material paste. The end of the insulator base plate is coated with a conductive material solution which becomes the common bus. The conductive material solution and resistive material paste may be cured at an elevated temperature.

United States Patent 1191 Przybylek 1 June 10, 1975 GASEOUS DISCHARGE DISPLAY PANEL WITH SCANNING ANODE BASE PLATE ASSEMBLY INCLUDING RESISTIVE MASSES [75] Inventor: George John Przybylek,

Martinsville, NJ.

[73] Assignee: Burroughs Corporation, Detroit,

Mich.

221 Filed: July 30,1974

211 App]. No.: 493,098

[52] U.S. Cl. 315/58; 313/217; 313/218;

[51] Int. Cl. H01j 17/34 [58] Field of Search 313/188, 217, 218, 220,

Primary ExaminerPalmer C. Demeo Attorney, Agent, or FirmFranklin D. Ubell; Leon E. Redman; Kevin R. Peterson [57] ABSTRACT A display panel including an array of gas-filled cells being arranged in upper display and lower scan sections of aligned cells with upper and lower cell pairs separated by a common cathode electrode. The lower scan section is further defined by scanning anode strips applied into slots formed in a lower insulator base plate with discrete resistive masses filling a portion of the slots while bridging a discontinuity in the applied scanning anode provided in a ledge area of the base plate. A common bus formed across the end of the base plate ledge forms a single electrical terminal interconnecting the scanning anodes for connection to an external power supply. In the method of making the display panel a conductive material solution is applied to the floor of the lower insulator base plate slots in an operation that is interrupted for providing the discontinuity therein which is filled by a discrete mass of resistive material paste. The end of the insulator base plate is coated with a conductive material solution which becomes the common bus. The conductive material solution and resistive material paste may be cured at an elevated temperature.

7 Claims, 8 Drawing Figures s Il' 12 SHEET PATENTED JUN 10 I975 Fig. 2

I V R PATENTEDJUH 10 I975 3.889.150

2 SHEET 3 Fig.6 33

16 F i g. 7

GASEOUS DISCHARGE DISPLAY PANEL WITH SCANNING ANODE BASE PLATE ASSEMBLY INCLUDING RESISTIVE MASSES BACKGROUND OF THE INVENTION Gas display panels are known having two layers of cells utilizing a plurality of cathode strips each having across its length tiny apertures interconnecting pairs of gas cells in the upper and lower layers, thus forming an array of such apertures. A cathode glow is established and transferred along the rear or scan side of the cathodes about the tiny apertures as the lower layer of cells is continuously scanned. As information signals are applied to display anodes of the upper layer of cells in synchronism with the scanning of its lower layer of cells, the cathode glow spreads from the scanside of the common cathodes to the display side at the addressed cells thus forming a visible character at the display surface of the panel.

For a more complete understanding of this scanning operation as related to gas display panels reference may be made to US. Patent Application Ser. No. 255,133, filed on May 19, 1972, of common ownership herewith, and now abandoned.

In order for the cathode glow to be properly maintained in the lower scan layer of cells, it is essential to apply a constant voltage to all of the scan anode wires, which are usually seated in grooves formed in the base plate. In the past these scan anode wires were individually connected to a power supply associated with an external driver circuit board through individual current limiting resistors. These current limiting resistors were mounted on this external driver circuit board and were attached to the respective scan anode wires by individual lead wires and individual connector terminals. Mounting the current limiting resistors on the driver board added to the overall cost and complexity of its fabrication. Besides, if one or more of the lead wires attached between the scan anode wires and the driver circuit board became loose then the lower layer of cells in the display panel could not be properly scanned due to the faulty connection to the power supply.

It is, therefore, an object of this invention to obviate mounting current limiting resistors on separate driver circuit boards.

It is another object of this invention to improve the integrity of the connection of an individual current limiting resistor with its associated scan anode.

It is still another object of this invention to reduce the number of external connections between the display panel scan anodes and power supply to one.

Accordingly, the display panel of the present invention includes an elongated insulator base plate assembly in which scan anodes are applied onto the floor of slots formed in an insulator base plate with each applied scanning anode having a single discontinuity. A discrete mass of resistive material is contained in the base plate slots and bridge each scanning anode discontinuity. A common bus is coated on the end of the base plate enabling a unitary external connection for all of the scanning anodes.

Other objects, advantages and features of this invention will become more fully apparent when considered with the accompanying detailed description, appended claims, and drawing in which:

FIG. 1 is a perspective view ofa gas cell display panel incorporating the self-contained scanning anode resistor arrangement of the present invention, with a portion of the panel cut away.

FIG. 2 is a sectional view of the panel of FIG. 1, taken along line 2-2 thereof.

FIG. 3 is an enlarged perspective view of the ledge area of the panel insulator base plate assembly.

FIG. 4 is a sectional view taken along line 44 of FIG. 3.

FIG. 5 is an enlarged perspective view ofa ledge area of the slotted insulator base plate having scanning anodes applied thereto according to the method of the present invention.

FIG. 6 illustrates the completion of the scanning anodes after a discontinuity has been provided therein.

FIG. 7 shows a portion of the slot filled with resistive material paste bridging the discontinuity of the applied scanning anodes. 1

FIG. 8 illustrates the coating of a common bus to a portion of the end of the insulator base plate according to the method of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 to 4 a portion of an insulator base plate assembly of a gas cell display device 10 is shown including a base plate 12 formed of suitable insulating material such as glass, ceramic or plastic. A plurality of parallel slots or channels 14 are formed in the base plate 12 and preferably extend completely thereacross. These slots 14 may be of generally rectangular cross section. Of course, the slots could be of any suitable cross section such as U-shaped or V-shaped.

The slots 14 formed into the upper surface 26 of the base plate 12 serve a number of functions in the con struction and operation of the gas display panel 10. Primarily, the slots 14 receive and properly orient an array of scanning anodes 16 disposed on the floors 30 of the slots. The slots 14 also keep the scanning anodes l6 spaced apart from each other and spaced below the upper surface 26 of the base plate 12. The slots also contain current limiting resistive masses 22 which bridge a discontinuity 20 provided in each of the scanning anodes 16 with which the resistor masses 22 are in physical contact. The discontinuities 20 as bridged by the resistive masses 22 are preferably disposed in a ledge portion 33 of the insulator base plate 12 extending beyond the sealed assembly 55 of the display panel 10.

An array of scanning cathodes (FIGS. 1 and 2) are seated on the upper surface 26 of the slotted base plate 12. These scanning cathodes are parallel to each other and are oriented generally perpendicular to the scanning anodes 16 in the base plate slots 14. The scanning cathodes 70 have a plurality of tiny apertures 100 (FIG. 2) disposed along their length at the intersection with an underlying scanning anode 16. The region where each scanning cathode 70 crosses a scanning anode 16 defines a gas cell 80, which is designated a scanning cell. The tiny apertures 100 in the scanning cathodes 70 interconnect the scanning cells aligned with an array of display gas cells formed in an apertured upper insulator plate seated on the scanning cathodes 70.

An array of display anodes are disposed on the upper surface of the upper insulator plate 110 such that each display anode 130 intersects a plurality of display cells 90 formed in the upper insulator plate 110.

A transparent viewing plate 150 is sealed with the apertured insulator plate 110 and the slotted base plate 12 by means of glass frit 170 or other suitable sealing material thereby forming the upper and lower boundaries of aligned pairs of gas cells 80, 90 in an hermetic unit 55.

For a more detailed description of the completion of the display panel 10, reference may be made to US. Pat. No. 3,683,222 issued on Aug. 8, 1972 and assigned to the assignee of the present invention.

In the method of constructing an insulator base plate assembly 11, utilized in the gas cell display panel of the present invention, referring to FIGS. 5 to 8, a first array of scanning anodes 16 is applied to the floor 30 of the base plate slots 14. The scanning electrodes 16 may be initially applied in the form of a conductive material solution 40, for instance, a silver palladium ink or silver resinate ink solution, by apparatus such as applieator 42 (FIGS. 5 and 6). All of the scanning anodes 16 are preferably applied simultaneously with the relative movement of the slotted base plate 12 and a set of applicators 42 (FIG. 5). The application of conductive material solution 40 from the applicators 42 onto the floor 30 of the base plate slots 14 may be interrupted for a predetermined length of the floor 30, thereby providing a discontinuity or gap of a desired length in each of the scanning anodes 16. The discontinuity 20 is located near one end 32 of the body of the base plate 12 in the ledge portion 33 in order to leave the maximum area possible for completing sealed assembly 55 of the panel 10.

After the predetermined length gap 20 has been left in the scanning anode l6, conductive material 40 is further applied onto the floor 30 of the base plate slots 14 forming a scanning anode ledge portion 18 extending substantially to the end 32 of the body of the base plate 12.

If desired, the conductive material solution 40 may be applied to the end 32 of the body of the base plate 12 (FIG. 6) providing a small lip 44 on the still exposed floor 30 for receiving a slightly increased amount of common stripe material 60 which is to be coated onto the end 32 as explained hereinafter.

The end opposite the ledge portion of the scanning anode 16 need not extend beyond the area of the sealed assembly 55 (FIG. 2).

Individual masses 22 of resistive material paste are filled into the slots 14 directly over the discontinuity 20 of each of the applied scanning anodes 16. The individual mass 22 of resistive material paste bridges the discontinuity 20, physically contacting the opposed inside surfaces 52 of the scanning anode 16 which define the boundary of the discontinuity 20. Furthermore, the individual mass 22 of resistive material paste extends slightly beyond the discontinuity 20, physically contacting the upper surface of the scanning anode 16 at region 50 (FIG. 4). Thus, the integrity of the scanning anode and resistor connection is improved.

The composition of the resistive material paste may be thallium oxide or a suitable glass frit. The resistance of each mass 22 depends on its composition and overall dimension. The ohmic value of the discrete masses of resistive material may be adjusted by varying the scanning anode discontinuity 20 which it bridges, or by varying the width of the slot 14 that contains it, or even varying the height of the mass.

The preferred technique for establishing the ohmic value of the resistive mass 22 is to choose an appropriate discontinuity length and fill the groove 14 to the upper surface 26 of the base plate 12. This enables the masses 22 of resistive material paste to be doctor bladed into the slots 14 by a doctor blade 71, eliminating the need for precise measurement and machining to other various heights. (FIG. 7).

A common bus 24 coated across the end 32 of the body of the base plate 12 interconnects all of the scanning anodes l6 and provides a single common terminal for connection to an external power supply (not shown). The common bus 24 is formed from a coating of conductive material 60 which may be applied to the base plate end 32 by a roller 72 (FIG. 8).

The composition of the coating may be the same as the scanning anode solution 40, for example a silver resonate ink or silver palladium ink. As can be seen in FIGS. 1, 2, and 8 the common bus coating 24 does not need to extend upward on end 32 beyond the scanning anode ledge portions 18.

If a lip 44 has been provided on the floor 30 of the slot 14, as previously described, then the common bus coating 24 will be rolled onto the end 32 of the base plate up to a sufficient height so that a portion 62 of it rests on the lip in physical contact with the ledge portion 18 of the applied scanning anodes16 (FIG. 2),

Any suitable connector (not shown) may be coupled to the common bus 24, for connecting it to a power supply (not shown) via a single lead wire 25. If desired, the single lead wire 25 to the power supply may be directly soldered to the common bus 24 (FIG. 1). Alternately, the single lead wire 25 may be adhered to the common bus 24 by an electrically conductive epoxy resin.

In the preferred method of manufacturing the insulator base plate assembly 11 of the present invention, the conductive solution forming the scanning anodes 16, the coating forming the common bus 24 and the slot contained mass 22 of resistive material paste are all simultaneously cured in a drying oven at a temperature of approximately C for between approximately 5 to l5 minutes. Alternately, the insulator base plate assembly 11 may be fired in an air atmosphere. The temperature range necessary is dependent on the melting point of the base plate material. Using glass of the type commonly used for display panel base plates, a temperature of approximately 400 to 590C is preferred.

After the scanning anodes 16, common bus 24 and resistive masses 22 have been fabricated along with the insulator base plate into the insulator base plate assembly 11 as described above, the display panel is completed as previously set forth.

Although preferred embodiments of the present invention have been described in detail, it is not intended that the invention should be limited by the description but only in accordance with the scope of the appended claims.

What is claimed is:

1. A base plate assembly for a gas cell display panel comprising:

an insulator base plate having a plurality of slots formed therein with floors for receiving a plurality of scanning anodes;

a plurality of scanning anodes disposed on the floors of said slots with a discontinuity provided in each of said scanning anodes;

a resistive mass contained within each of said slots and bridging each of said discontinuities; and

a common bus provided across one end of said insulator base plate and coupled to said scanning anodes for providing a single terminal for coupling said scanning anodes with an external power sup- P y- 2. The gas cell display panel of claim 1 wherein said scanning anodes in said slots extend substantially to the end of said insulator base plate providing an exposed lip portion of the floor of each of said slots and wherein said common bus extends onto said lips.

3. The gas cell display panel of claim 1 wherein said scanning anodes and said common bus comprise silver palladium.

4. The gas cell display panel of claim 1 wherein said resistive mass comprises thallium oxide. I

5. A gas cell display panel comprising:

an insulator base plate having a plurality of slots formed therein, at least some of said slots having floors for receiving a plurality of scanning anodes;

a plurality of scanning anodes disposed on the floors of said slots with a discontinuity provided in each of said scanning anodes;

a plurality of scanning cathodes seated on said insulator base plate and intersecting the scanning anodes on the floors of said slots, each intersection of said scanning anodes and said scanning cathodes defina common bus provided across one end of said insulator base plate. said common bus cooperating with said scanning anodes for providing a single terminal for connecting said scanning anodes with an external power supply. 1 6. The .gas cell display panel of claim 5 wherein said insulator base plate includes a ledge portion extending beyond said sealed display unit and wherein said scanning anode discontinuities bridged by said resistive masses are disposed in said ledge portion of said insulator base plate.

7. The gas cell display panel of claim 6 wherein said common bus is provided across the end of said ledge portion of said insulator base plate. 

1. A base plate assembly for a gas cell display panel comprising: an insulator base plate having a plurality of slots formed therein with floors for receiving a plurality of scanning anodes; a plurality of scanning anodes disposed on the floors of said slots with a discontinuity provided in each of said scanning anodes; a resistive mass contained within each of said slots and bridging each of said discontinuities; and a common bus provided across one end of said insulator base plate and coupled to said scanning anodes for providing a single terminal for coupling said scanning anodes with an external power supply.
 2. The gas cell display panel of claim 1 wherein said scanning anodes in said slots extend substantially to the end of said insulator base plate providing an exposed lip portion of the floor of each of said slots and wherein said common bus extends onto said lips.
 3. The gas cell display panel of claim 1 wherein said scanning anodes and said common bus comprise silver palladium.
 4. The gas cell display panel of claim 1 wherein said resistive mass comprises thallium oxide.
 5. A gas cell display panel comprising: an insulator base plate havinG a plurality of slots formed therein, at least some of said slots having floors for receiving a plurality of scanning anodes; a plurality of scanning anodes disposed on the floors of said slots with a discontinuity provided in each of said scanning anodes; a plurality of scanning cathodes seated on said insulator base plate and intersecting the scanning anodes on the floors of said slots, each intersection of said scanning anodes and said scanning cathodes defining a scanning cell; an upper insulator plate having an array of display cells formed therein and aligned with said scanning cells; an array of display anodes disposed on said upper insulator plate and intersecting a plurality of said display cells, said upper insulator plate and said base insulator plate being sealed together to form a sealed display unit; a resistive mass contained within said slots having floors for receiving scanning anodes, and said resistive mass bridging each of said discontinuities formed in said scanning anodes; and a common bus provided across one end of said insulator base plate, said common bus cooperating with said scanning anodes for providing a single terminal for connecting said scanning anodes with an external power supply.
 6. The gas cell display panel of claim 5 wherein said insulator base plate includes a ledge portion extending beyond said sealed display unit and wherein said scanning anode discontinuities bridged by said resistive masses are disposed in said ledge portion of said insulator base plate.
 7. The gas cell display panel of claim 6 wherein said common bus is provided across the end of said ledge portion of said insulator base plate. 